NERI technical report no. 538: Heavy metals in seaweed and blue mussels at Ivittuut 2004. Johansen, P. & Asmund, G. 2005. 28 pp.

 

English summary

 

In Ivittuut at Arsuk Fjord in South Greenland the mineral cryolite ore was mined, sorted and shipped out from 1854 to 1987. The mining operations have caused pollution with lead and zinc of the fjord. The main source is waste rock, which has been left at the coastline and is releasing lead and zinc to the fjord from tidal water action.

 

The pollution of the fjord has been monitored since 1982. Since 1985 this monitoring has only included seaweed and blue mussels, since earlier studies had shown that fish and prawns from the fjord were not affected by the lead and zinc pollution. This report presents the results of the latest environmental study, which was carried out in 2004.

 

The geographical pattern of lead and zinc levels found in brown seaweed and blue mussels in 2004 shows that waste rock in Ivittuut still is the main source of the pollution of the fjord.

 

In brown seaweed elevated lead levels were found on a c. 7-km stretch of coastline in eastern Arsuk Fjord around Ivittuut, whereas zinc levels were elevated on most of the coastline studied in Arsuk Fjord. In blue mussels elevated lead levels were seen in all of the studied parts of Arsuk Fjord, but also on coasts 3-4 km outside the fjord.

 

Along a stretch of coastline of c. 10 km around Ivittuut the lead concentration in blue mussels is so high that it is recommended not to eat blue mussels from this area. The area has not changed since 1992, but earlier it included a larger part of the coastline in the fjord.

 

From 2001 to 2004 no consistent changes for lead and zinc are apparent, as lead and zinc levels in seaweed and blue mussels have increased in some areas but have decreased in others. However over the entire monitoring period (1982 to 2004) lead levels have declined in Arsuk Fjord. On the contrary no consistent changes for zinc are apparent for the entire monitoring period.

 

Full report in danish inpdf format  (417 kB).